Mineral lubricating oil containing high molecular weight alkyl substituted phenolic sulfonamide

ABSTRACT

Polymethylene polyamine sulfonamides of alkyl-substituted phenolic sulfonic acids wherein the alkyl-substituent has a molecular weight within the range of 400 to 3000 are novel compounds soluble in mineral hydrocarbon oils of the lubricating oil range and as solutes therein are ashless addition agents imparting to the solution a combination of anti-oxidant and detergency-dispersancy properties useful in the lubrication of internal combustion engines. Illustrative of such sulfonamides are mono- and disulfonamides of hexamethylene diamine, tetraethylene pentamine, 2,6-di(aminoethyl) pyridine and N,N&#39;&#39;di(aminopropyl) piperazine with 4-alkylphenolic sulfonic acids such as 4-alkyl-1-hydroxyphenyl, 4,4&#39;&#39;-dialkyl-1,1&#39;&#39;-dihydroxy2,2&#39;&#39;-biphenyl, 4-alkyl-1-alkoxyphenyl or 2-tri- and tetra-(4&#39;&#39;alkyl-1-hydroxybenzyl)-substituted 4-alkyl-1-hydroxyphenyl sulfonic acid chlorides.

United States Patent Karll et al.

[ 1 July4, 1972 [54] MINERAL LUBRICATING OIL CONTAINING HIGH MOLECULARWEIGHT ALKYL SUBSTITUTED PHENOLIC SULFONAMIDE [72] Inventors: Robert E.Karll, Munster, lnd.; Richard J.

Lee, Park Forest, 111.

[73] Assignee: Standard Oil Company, Chicago, Ill. [22] Filed: April 1,1970 [21] App1.No.: 24,807

[52] vU.S. Cl. ..252/47.5, 260/268 S [51] Int. Cl. ...Cl0m l/40,Cl0m1/36 [58] Field of Search ..252/33, 47.5

[56] References Cited UNITED STATES PATENTS 2,236,168 3/1941 Dietrich..252/47.5 3,325,418 6/1967 Stuart .....252/47.5 X 3,328,297 6/1967Anderson. .....252/47.5 X 2,287,639 6/1942 Pings ..252/47.5 X

Primary Examiner-Daniel E. Wyman Assistant Examiner-W. CannonAttorney-Arthur G. Gilkes, William T. McClain and Fred R. Ahlers [57]ABSTRACT Polymethylene polyamine sulfonamides of alkyl-substitutedphenolic sulfonic acids wherein the alkyl-substituent has a molecularweight within the range of 400 to 3000 are novel compounds soluble inmineral hydrocarbon oils of the lubricating oil range and as solutestherein are ashless addition agents imparting to the solution acombination of anti-oxidant and detergency-dispersancy properties usefulin the lubrication of internal combustion engines. Illustrative of suchsulfonamides are monoand disulfonamides of hexamethylene diamine,tetraethylene pentamine, 2,6-di(aminoethyl) pyridine andN,N'-di(aminopropyl) piperazine with 4-a1- kylphenolic sulfonic acidssuch as 4-alkyl-l-hydroxyphcnyl, 4,4-dialkyl-l ,1-dihydr0xy-2,2'-biphenyl, 4-alkyll -alkoxyphenyl or 2-triandtetra-(4'-alkyl-l-hydroxybenzyl)-substituted 4-alkyl-l-hydroxyphenylsulfonic acid chlorides.

5 Claims, No Drawings MINERAL LUBRICATING OIL CONTAINING HIGH MOLECULARWEIGHT ALKYL SUBSTITUTED PI-IENOLIC SULFONAMIDE BACKGROUND OF THEINVENTION Sulfonamides of aromatic hydrocarbon sulfonic acids and phenolsulfonic acids having nuclear substituents comprising rather short chain(hence low molecular weight) substituted alkyl groups are known buttheir limited solubility in mineral oils of lubricating oil types havemade them unattractive as additives for formulating lubricant oilcompositions. The sulfonamides are nonionic surfactants, are more stablethan amine salts of sulfonic acids and are capable of combustion toash-free (no metallic residue) products. However, their suitability asuseful lubricant oil addition agents has been somewhat neglected in partbecause of their limited solubility in lubricating oils and in part bythe lack of sulfonic acid precursors having suitable oil solubilizingcharacteristics. In a copending application phenolic sulfonic acidaffording compounds, i.e. sulfonylides which are intermolecular sulfonicacid esters and sulfonic acid chloride, and their preparation by uniquesulfonation and chlorosulfonation are described. Those phenolic sulfonicacid affording compounds because of the nature and character of theiralkyl-substituents do permit the preparation of sulfonamides of suitableoil solubility to provide sulfonamides useful in formulating lubricantoil compositions for use in lubricating internal combustion engineswhere heat stability and ash-free properties of the sulfonimide can beused to advantage.

SUMMARY OF INVENTION The class of sulfonamides of this invention can beillustrated by the general formula:

H O Z- NYNX wherein X is hydrogen or a group, Y is a. divalentpolymethylene group having 0 to l divalent O '--Z-OH Y is a divalentpolymethylene group having 0 to l divalent pyridyl or piperazinyl bridgebetween such methylene groups and Z is a 4-alkylphenyl group with thehydroxyl group in the l-position on the benzene ring. Said sulfonamidesare obtained by the reaction of a polymethylene polyamine, hereafterfurther described, which has two primary amino groups: H N and aphenolic sulfonic acid precursor which is a sulfonylide or a sulfonicacid chloride as follows wherein Equation (I) illustrates reaction ofequimolar proportions diamine and sulfonylide and Equation (II)illustrates reaction of the diamine with sulfonic acid chloride:

The reaction illustrated by Equation (I) can be modified by the use oftwo moles of diamine per mole of the sulfonylide to provide amonosulfonamide product. The reaction of Equation (II) also can bemodified to provide the disulfonamide product through the use of twomoles of phenolic sulfonic acid chloride per mole of diamine.

EMBODIMENTS OF THE INVENTION Representative diamines include diaminoalkanes having from one to divalent methylene groups (CH between theamino groups, for example methylene, ethylene,

propylene, butylene, pentamethylene, hexamethylene, heptamethylene,octamethylene, nonamethylene and decamethylene diamine;N,N'-disubstituted piperazine and nuclear 2,6-disubstituted pyridinewherein each have the substituents aminomethyl, aminoethyl, aminopropyl,aminobutyl, aminopentyl, aminohexyl, aminoheptyl, aminoctyl, aminononyl,and aminodecyl groups; and polymethylene polyamines of the structure l-IN[(Cl-I ),.NI-I],, -l-l WHERE N is a number of from 1 to 10, preferably2 and 3, and m is a number from 2 to l l. The polymethylene polyaminesare polyanalogs of the diaminoalkanes. The preferred polymethylenediamines include di-, tri-, tetra-, penta-, hexa-, hepta-. octa-, nona-,and deca-ethylene and propylene tri-, tetra-, penta-, hexa-, hepta-,octa-, nona-, deca-, and undecaamines. Also said polymethylenepolyamines can be polymers of ethylene imine of LOGO-4,000 molecularweight.

Representative precursors of the phenolic sulfonic acid moiety of thepresent inventive sulfonamide are as mentioned before aryl sulfonylidesand l-hydroxyphenyl sulfonic acids chlorides having a 4-nuclearalkyl-substituent of 4003,000 molecular weight.

The alkyl-substituted sulfonylide reactant can be illustrated by thestructure of the sulfonylide of 4-alkyl-l-hydroxyphenol as follows:

wherein R is the nuclear alkyl-substituent of 400-3,000 molecularweight. Said alkyl group R can be derived from wax paraffin hydrocarbonswherein the mixture of hydrocarbons have an average molecular weight inthe range of 4006,000. The sulfonylide is obtained by sulfonating witholeum of 20-40 weight percent a 4-alkyl-substituted phenol which in turnis obtained by the alkylation of a phenol with a monochlorinated waxparaffin of suitable size within the range of 400-3,000 molecular weightor with a liquid viscous polypropene or polybutene (propene or butenepolymerized in the presence oiAlCl of appropriate number averagemolecular weight (Mn) in the range of 400 to 3,000.

The phenolic sulfonic acid precursor can be 4-alkyl lhydroxy-benzene2-sulfonic acid chloride:

on Q-s 0201 or 4-4'-alkyll ,l '-hydroxy-2,2'-biphenyl-6,6'-disulfonicacid chloride:

]OH [OH 1 1 CH2 CHz l l R R wherein A is a number of from 2 to 3. Saidtriand tetra-(4'alkyl-1-hydroxybenzyl)-substituted4-a1kyl-1-hydroxybenzene sulfonic acid chloride reactants are obtainedby chlorosulfonating the respective products from the condensation of 4and moles of 4-alkylphenol with formaldehyde. in all of the foregoing Ris the nuclear alkyl-substituent of 400 to 3,000 molecular weight.

When the sulfonic acid chloride is the reactant, a hydrogen chlorideacceptor which will combine (i.e. as a HCl salt) or react with HCl toform a water soluble product is used. Pyridine is the preferred HClacceptor. Such combination or reaction product with HCl can be readilyremoved from the sulfonamide product by water washing since the presentinventive sulfonamides are not appreciably soluble in water.

lLLUSTRATlVE EXAMPLES The following examples will illustrate severalspecies of the present inventive sulfonamides and their preparation aswell as their use in lubricant oil compositions.

EXAMPLE I There are combined and stirred at ambient temperature 0. 1mole sulfonylide of 4-alkyl-l-hydroxy sulfonic acid wherein the alkylgroup is a polypropyl group of 400 Mn and tetraethylene pentamine (TEPA)in the respective molar ratio of reactants of 1.0220. The sulfonylide(1,1 16 M.W.) is used as a 40 weight percent solution thereof in SAE 5Woil. The stirred mixture is heated to about 120C. for 1 hour. Thereaction product is a solution having 42 weight percent of mono-4-alkyl-l-hydroxybenzene sulfonamide of tetraethylene pentamine and about3.94 weight percent nitrogen.

EXAMPLE 2 .Example 1 is repeated except that 0.2 mole each of thesulfonylide and TEPA are reacted. The resulting product is a 40 weightpercent solution of N,N -di-4-a1kyl- 1 -hydroxybenzene sulfonamide ofTEPA having about 2.25 weight percent mtrogen.

EXAMPLE 3 Example 2 is repeated except the commercial mixtures ofpolyalkylene polyamines having the molecular weight and nitrogen on theaverage equal to tetraethylene pentamine but only about 70 percent ofthe molecules are linear [i.e. H N (C H,NH),H] and the remaining 30percent of the molecules have branched aminoethyl groups attached tolinear chain, therefor tertiary, nitrogens. The resulting sulfonamidehas 2.25 percent nitrogen.

EXAMPLE 4 There are combined and stirred 0.3 mole of 4-alkyl-1-hydroxy-benzene sulfonic acid chloride (alkyl group is 885 Mn polybutyl)and 0.3 mole pentaethylene hexamine (PEHA) dissolved in 200 ccs pyridinein a reaction vessel having, in addition to a stirrer, an inlet forcharging liquid, a gas inlet and a gas outlet. The sulfonic acidchloride is charged as a 50 weight percent solution thereof in SAE 5Woil. The solution of PEHA is added rapidly to the stirred solution ofthe sulfonic acid chloride starting at ambient temperature. After allthe PEHA is added the stirred mixture is heated to 130135C., nitrogengas is injected into the hot liquid to remove pyridine and water in theexhaust gas. Then 56 grams of CaO suspended in SW oil are added. Thedried mixture is filtered. The filtrate solution contains 61 weightpercent of the mono-4-alkyl-1-hydroxybenzene sulfonamide of PEHA andabout 4 weight percent nitrogen.

EXAMPLE 5 A stirred solution of 430 grams (0.3 mole)4-alkyl-lhydroxyphenol sulfonic acid chloride of 1,434.5 Mn (alkyl ispolybutyl group of 1,307 Mn), 504 grams SAE 5W oil and 2,000 ml hexaneis prepared at ambient temperature in a reactor having a stirrer,electric heat mantle, inlet for charging liquid and gas inlet forintroducing gas into liquid contents. To the stirred solution there arerapidly added 60 grams (0.312 mole) TEPA dissolved in ml of pyridine and20 grams sodium hydroxide dissolved in 50 ml. ofwater. Therealter themixture is heated to and maintained at a temperature ot- 300F. for 1hour while injecting nitrogen gas into the reaction liquid. The nitrogengas injection aided the removal of hexane, pyridine and water. Theresulting solution of mono-sulfonamide of TEPA in oil is diluted with200 grams of SAE 5W oil (704 grams total oil) and filtered to removesodium chloride and unreacted sodium hydroxide. The filtrate contains40.5 weight percent of N-(4-alkyl-1-hydroxyphenyl) sulfonamide ofTEPAand has a nitrogen content of 147 Weight percent.

EXAMPLES 6 to Following the procedures ol Example 4 there are preparedthe sulfonamides ol'the structure:

wherein A is hydrogen or methyl, by reaction of substantially equalmolecular proportions of tetraethylene pentamine with the appropriate4-alkyl-l-hydroxyphenyl sulfonic acid chloride to provide thesulfonamide having the R substituent indicated in Table l by the Mn ofthe alkyl-substituent R and the nature of A. Table 1 also indicates theconcentration in weight percent of the sulfonamide in SAE 5W oil and thenitrogen content in weight percent of the solution.

TABLE I Oil solution Sulfonamide R-substitncnt concon- Nitrogen tration,content, Example A Type Mn percent percent 6 Hydrogen... Polylmtyl...1,600 44 1.00 ..d0 Polypropyl. 800 40 l7 Methyl lolyhntyl. 1,600 -10 1.01Iy 1r0gun lolypropyL. 700 00 K'.

sulfonamidez ()lI (|)1l one soz rr'(cilmi ll l I It 3 R EXAMPLES 10 to12 Following the procedure of Example 4 there are prepared thesulfonamides of the structure:

by reaction of substantially equal molecular proportions ofpentaethylene hexamine with the appropriate 4-alkyl-lhydroxyphenylsulfonic acid chloride to provide the R group substituent indicated inTable 11 which also indicates the weight percent concentration of thesulfonamide and nitrogen content of the SAE 5W oil solution.

TABLE ll The utility of the present inventive sulfonamides can bedemonstrated by their use in lubricating oils which are subjected to lowseverity dispersancy test, high severity dispersancy test. Those testsare conducted in the following manners.

Low Severity Dispersancy Test A measured amount of sulfonamide isdissolved in 20 grams of used crankcase oil containing sludge. Themixture is stirred and heated to 300F. and held at that temperature for3 hours. Five drops of hot oil (300F.) are spotted on blotter paper andheld at ambient temperature (about 77F.) After 3, 19 and l 50 hours atambient temperature, each spot is measured with respect to outer clearoil ring and inner concentric sludge ring. The ratio of sludge ring areato oil ring area X100 is determined as a number evaluation ofsludgedispersing efficiency.

High Severity Dispersancy Test This test is similar to the Low SeverityDispersancy Test except the mixture of sludge in oil solution ofcandidate sulfonamide is stirred and heated to 320F. for 20 hours beforethe drops were spotted on blotter paper which is then held at ambienttemperature for 3 hours, 19 hours and 12 days before measuring the clearoil ring and sludge ring and determining their areas for calculating theratio of said areas X100 to obtain dispersing efficiency number value.

The results of those two tests are reported in Tables IV and V below forthe use of candidates selected from the foregoing sulfonamide examples.sulfonamide concentration in the used crankcase oil (20 grams) isreplaced in grams of sulfonamide per 20 grams of sludgy used crankcaseoil.

TABLE IV Low Severity Dispersancy Test sulfonamide Tested Hours AfterSpot Deposit Example Concentration 3 19 150 Control 0 54 54 54 6 1 notmeasured 65 54 7 1 not measured 73 58" 7 2 100 100 74" l l I notmeasured 78 56" l l 2 I00 I00 86 "Three weeks after spot deposit. *24()Hours after spot deposit. "240 Hours after spot deposit and 77 after 30days.

TABLE V High Severity Dispersancy Test sulfonamide Tested Time AfterSpot Deposit Example Concentration 3 hr. 19 hr. 12 days 7 l 86 66 Y 55 72 100 not measured 8l 1 l l 80 64 56 l l 2 100 100 88 l2 1 I00 68 58 122 I00 I00 83 EXAMPLE 13 The monosgfonamide of N,N'-di(aminopropyl)piperazine and 4-alkyl (Mn 2,000 polybutyl)-l-hydroxyphenyl sulfonicacid having the structure:

wherein R is said 2,000 Mn polybutyl group is prepared using SAE-5W oildiluted as described in Example 3. The oil solution contains about 40percent sulfonamide and 1.0 percent nitrogen on a weight basis.

The oil solution of the sulfonamide of Example 13 is used to supplydetergent for the following crankcase oil formulation wherein theingredients named are used on a volume percent basis.

ingredient Amount-Vol.

Oil solution product of Example l3 The zinc dialkyldithiophosphate usedhad primary alkyl groups and the zinc salt content of the oil solutionis percent by weight. The calcium alkylbenzene sulfonate oil solutioncontained 40 weight percent of the calcium salt.

The above oil formulation using the product of Example 13 is used ascrankcase lubricant in a Caterpiller Diesel Engine operated under thestandardized Caterpiller Engine Test 1H conditions for 240 hours. At theend of this test the efficiency of in-service use of said crankcase oilformulation was evaluated by inspection of engine piston with respect todeposits in top ring groove, on first land and in second ring groove.The results found are:

Top Groove Filling 2% First Land Coating 60% Second Groove Filling 50%Use of the same crankcase oil formulation without the sulfonamide wouldresult in 25 percent fill of top groove, 60 percent coating of firstland and 70 percent fill of second groove.

EXAMPLE 14 The process of Example 1 is repeated using a4-polypropylkhydroxy benzene sulphonyl chloride (polypropyl group has Mn753) and TEPA in a 0.2-1.0 mole ratio. The resulting sulphonamide ofTEPA has a Mn of l ,097. The product resulting from this examplecontains 42 weight percent of said sulphonamide and has a nitrogencontent of about 2.3 weight percent.

EXAMPLE 15 The process of Example 14 is repeated using a 4-polypropyll-hydroxy benzene sulphonyl chloride (polypropyl group has Mn753) and TEPA ir i a l.0:l.0 mole ratio. The resulting disulphonamidehas a Mn of 2,010. The product from this example contains about 40percent of said disulphonamide and has a nitrogen content of 1.2 weightpercent.

What is claimed is:

l. A mineral lubricating oil composition having dissolved therein 33-60weight percent of said composition of high molecular weightalkyl-substituted phenolic sulfonamide of group Y is polyaminoethylenegroup having two to C H groups joined by one to nine NH- groups or N,N-di(propene) piperazine; and Z is 4-alkylphenyl group wherein the alkylgroup has a molecular weight from 400 to 3,000.

2. The composition of claim 1 wherein the alkyl substituent of Z ispolypropyl or polybutyl of 400-3,000 fi 3. The composition of claim 2wherein Y is N,N'- di(propylene) piperazine and X is hydrogen.

4. The composition of claim 2 wherein Y is C H NH and Z is said4-alkylphenyl.

2. The composition of claim 1 wherein the alkyl substituent of Z ispolypropyl or polybutyl of 400-3,000 Mn.
 3. The composition of claim 2wherein Y is N,N''-di(propylene) piperazine and X is hydrogen.
 4. Thecomposition of claim 2 wherein Y is - C2H4NH -4 and X is hydrogen. 5.The composition of claim 2 wherein Y is - C2H4NH -4, and Z is said4-alkylphenyl.